There are a number of ways known by those skilled in the art to fasten, couple, or connect items. For example, it has been proposed to taper the sides of a shaft so that the head portion consisting of, for example, a toothbrush or tool, may be attached thereto, while permitting removal and interchange of the head portion, as disclosed in U.S. Pat. Nos. 1,887,913 (Bell), 3,039,340 (Livermont), 3,182,345 (Smith) and 3,369,265 (Halberstadt et al). Also, intermeshing joints have been utilized for connecting in woodworking, as disclosed in U.S. Pat. Nos. 1,212,262 (Rockwell), 1,214,261 (Balbach), 1,342,979 (Beitner) and 1,954,242 (Heppenstall), and in metal working, as disclosed in U.S. Pat. Nos. 2,895,753 (Fentiman) and 3,000,658 (Sprouse). Further, inclined or tapered shafts have been utilized for interconnecting the ends of leather washers, as illustrated in U.S. Pat. No. 281,760 (Gingras). However, all of the above have utilized a single shaft and, in some instances, either provided protruding elements along the sides or a T-shaped like-end to provide additional mechanical interference to enhance fastening.
In addition, several fasteners have been disclosed in the art for attaching items together. For example, loops and hooks have been utilized whereby when the hooks are brought into contact with the loops the former interlocks with the latter, as disclosed in U.S. Pat. Nos. 2,717,437 (Mestra) and 3,009,235 (Mestra). Also, a plurality of macro asperities or protrusions have been utilized which may either be brought into contact with similarly shaped macro asperities or with correspondingly shaped recesses, as disclosed in U.S. Pat. Nos. 2,499,898 (Anderson), 3,192,589 (Pearson), 3,266,113 (Flanagan, Jr.), 3,408,705 (Kayser et al.), and 4,520,943 (Nielsen). In addition, fasteners utilizing a plurality of longitudinally extending rib and groove elements which deform and mechanically interfere and resiliently interlock with each other have been disclosed, for example, in U.S. Pat. Nos. 2,144,755 (Freedman), 2,558,367 (Madsen), 2,780,261 (Svec et al.), 3,054,434 (Ausnit et al.), 3,173,184 (Ausnit), 3,198,228 (Naito) and 3,633,642 (Siegel).
Further, containers of the type commonly known as "Tupperware" containers (Tupperware is a registered trademark of Kraft, Inc.) and the many similar containers are disclosed, for example, in U.S. Pat. Nos. 2,487,400 (Tupper), 3,335,774 (Reed), 3,618,802 (Yates, Jr.), 3,730,382 (Heisler), and 3,817,420 (Heisler). The covers of such containers are precisely sized and when mounted, the covers are stretched to cause a tension to be developed in the cover rims between inner and outer retaining lip portions to provide mechanical interlocking for closure.